Safety control and ignition apparatus for gaseous fuel burners



June 6, 1950 c. K. STROBEL 2.5103

smz'rv con'mor. AND IGNITION APPARATUS FOR GASEOUS FUEL BURNERS FiledDec. 7, 1946 3 Sheets-Shem 1 Gttomcg June 6, 1950 c K STROBEL 2,510,264

SAFETY coNTRbL AND IGNITION APPARATUS FOR GASEOUS FUEL BURNERS FiledD80. 7, 1946 3 SheetsSheet 2 [/VVE/VTOR CHARLES KENNEDY STROBEL,

June 6, 1950 c. K. STROB EL 2,510,264

I SAFETY CONTROL AND IGNITION APPARATUS FOR GASEOUS FUEL BURNERS FiledDec. 7, 1946 3 Sheets-Sheet 3 I I .T 166 172 164 7- 7" 5 Z';: II, I

"I 41/ 1M! i INVEN TOR CHARLES KENNEDY STROML,

a r TQENE r:

Patented Junefi, 1950 SAFETY CONTROL AND IGNITION APPA- RATUS FORGASEOUS FUEL BURNERS Charles K. Strobel', Pittsburgh, Pa., assignor toRobertshaw-Fulton Controls Company, a corporation of DelawareApplication December 7, 1946, Serial No. 714,788

9 Claims. 1

This invention relates to safety control and ignition apparatus forgaseous fuel burners and. more particularly, to electrically operatedapparatus for oven burners independent of commercial current supply.

In copending application Serial No. 620,320 filed October 4, 1945 byCharles K. Strobel et al. and assigned to the assignee of the presentapplication, there is disclosed a flash-tube ignition system embodying athermoelectric safety device. The system is placed in operation by theusual manipulation of the oven gas cock which 'may include thethermostatic control for oven temperatures. An automatic thermal timingdevice determines the so-called starting period during which thethermoelectric device comes into operation. Upon termination of thisperiod the fuel flow to the flash pilot burners is cutoff fortheduration of the oven operation and only the thermocouple heatingburner and the main burner remain in operation, the latter under controlof the oven thermostat.

An object of the present invention is to render such apparatus moreuseful by improving the automatic nature thereof.

Another object of the invention is to utilize simple and economicaltiming means cooperable with the existing controls to start and stop theapparatus at desired times.

Another object of the invention is to permit the setting of dualcontrols at one time for automatic operation in proper sequence at alater time in the absence of the operator.

Another object of the invention is to preserve all the existing safetyfeatures intact while improving the performance of the apparatus as aunit.

Other objects and advantages will become apparent from the followingdescription taken in connection with the accompanying drawings,

wherein:

Fig. 1 is a perspective view of a safety control and ignition apparatusfor an oven burner embodying the invention;

Fig. 2 is a longitudinal sectional view of the having the usual ovenburner l0 and top pilot burner l2 located remotely from the oven burner10. As is customary in equipment of this nature, the various burnersreceive fuel from the manifold l4 connected to a source of fuel supply.In this embodiment. the top pilot burner I2 is connected by a pipe IE tothe manifold 14 and is of the constant burning type.

The main oven burner I0 is supplied with fuel from the manifold 14 by amain fuel pipe 18 and the fuel supply therein is under control of meanscomprising a main fuel cook which may also embody the usual thermostaticcontrol device adelectromagnetic control device shown in Fig. 1;

Fig. 3 is an elevation of the resetting device for the control deviceshown in Fig. 2;

Fig. 4 is a front elevation of another portion of the resetting device;and

Fig. 5 is a plan view of the resetting device shown in Fig. 4.

Referring more particularly to Fig. 1 of the drawings, the safetycontrol and'ignition apparahis is shown in connection with a cookingrange justable together with the cock by knob 2| and being responsive totemperatures in the oven where the burner I0 is located. As combinedfuel cocks and thermostatic devices are well known, further descriptionis deemed unnecessary, it being understood that the thermostatic deviceis capable of controlling the flow of fuel in the pipe I8 independentlyof the fuel cock 20 when the latter has once been opened. The flow offuel in the pipe l8 to the main burner 10 is thus subject to thethrottling action of the thermostatic device where included.

The flow of fuel in the pipe I8 to the main burner I0 is also under thecontrol of a thermomagnetic control device designated generally by thereference numeral 22. This thermomagnetic control device 22 isinterposed in the main fuel pipe 18 in proximity of the top pilot burnerI2 between the main fuel cock 20 and the oven burner Ill. As shown moreclearly in Fig. 2, the control device 22 comprises a casing 24 having aninlet connection 26 extending through the sidewall of the casing 24adjacent one end and communicating with a main fuel chamber 28 extendingaxially of the casing 24. The main fuel chamber 28 is provided with apartition 30 having an opening 32 therethrough through which fuel mayflow from the inlet 26 to an outlet 34 formed in the wall of the casing24 at the opposite end of the chamber 28. The inlet 26 and outlet 34serve as connections for opposite ends of the fuel pipe l8 as will beapparent from Fig. 1 of the drawings.

The passage 32 is controlled by a safety valve 36 which is movable intoand out of engagement with a valve seat 38 formed on the side of thepartition 30 adjacent the inlet opening 26. The valve member 36 issecured to a valve stem 40 which extends to the opening 32 and hasslidable engagement with a closure disc 42. The purpose of the closuredisc is to interrupt the flow of fuel through the passage 32 when thevalve member to is moved out of engagement with the seat 38 during theresetting operation to be de scribed hereinafter. To this end, a secondvalve seat 341 is formed on the partition til on the side opposite thevalve seat and is adapted to be engaged by the closure disc 12 duringthe reset ting operation. A. guide portion is formed substantiallyconcentric with the closure disc 432 for cooperation with the walls ofthe opening 32 and may be serrated to permit free passage of fuelthereby until the closure disc is fully en= gaged with its seat Thebottom of the chamber 28 is provided with an annular projection orhousing as in which a stem portion ie of the closure disc d2 is slidablymounted. A coil spring is carried by the stem 48 and is operativebetween the housing do and a collar 52 mounted on. the stem d8. Thus,when a force is applied to the end of the stem ill to move the closuredisc 32 into engagement with its seat 44, the coil spring 553 will becompressed. When the force is removed, the bias of the spring 56 willserve to return the closure disc d2 toits open position relative to theseat it.

A yieldable connection is provided between the closure disc 42 and thevalve member so to permit relative movement therebetween as will be moreapparent hereinafter. To this end, there is provided an overridemechanism in association with the closure disc 42 and valve stem towhich may take the form of a coil spring 5 3 housed within an axialrecess in the closure disc stem to and operative between the bottom ofthe recess and the end of the valve stem it.

The end of the casing ZJQ adjacent the inlet 26 is provided with aclosure cap 56 having a magnet housing 58 closely engaging the innerwall there of. The closure cap at its outer end supports a threadedterminal connection so. The magnet housing 58 supports a horseshoemagnet 62 which is provided with the usual winding as having one endgrounded on the closure cap 58 and the op= posite end secured to theterminal connection 6b. The electromagnetic device is completed by theprovision of an armature 65 which is carried by the valve stem 46 forcooperation with the pole faces of the magnet 62. It will be noted thatthe armature is normally spaced from the magnet a less distance than theclosure disc 52 is spaced from its seat. Thus, after the armature is inattracted position the override spring 54 permits further movement ofthe closure disc relative to the valve stem 40. When the valve member 36is fully disengaged from its seat 38, then the armature 66 is inattracted relation relative to the pole faces of the magnet 62. Thevalve member 36 is biased to its seat 38 and the armature 66 to itsreleased position by the provision of a coil spring 68 operative betweenthe valve member 36 and the bottom of the magnet housing 58.

The control device 22 also includes means to control the supply of fuelto a flash pilot burner I0 and an auxiliary pilot burner 12. As shown inFig. 1, the flash pilot burner I0 is located in the oven compartmentadjacent the main burner I0 while the auxiliary pilot burner 12 islocated adjacent the top pilot burner I2. Both burners are supplied withfuel by a pipe 14 extending from the control device 22, the auxiliarypilot burner 12 being conveniently connected to pipe 14 by a branch pipe16. The inlet for fuel to the pipe 14 is connected to the control device22 and may take the form of a pipe 18 connected at the opposite end tothe main fuel cook 20. The fuel in the pipe 18 is preferably undercontrol of the main fuel cock 2t but is not controlled by thethermostatic device which may be included as previously described. Thus,when the main fuel cock 2b is open the flow of fuel in the pipe is isnot subject to the throttling action of the thermostatic device as isthe fuel in the pipe 58.

As previously indicated, the thermomagnetic control device 22 is alsoadapted to control the flow of fuel to the flash pilot burner to and theauxiliary pilot burner l2. To this end, as shown more clearly in Fig. 2,the pipe N3 is connected to an inlet opening 8t extending through thewall of the casing 26 and communicating with an auxiliary fuel chamber82 formed axially of the casing and separated from the main fuel chamber28 by the housing at. In order to prevent leakage of fuel from onechamber to the other, the auxiliary fuel chamber 32 is provided with adiaphragm es extending thereacross adjacent the end of the closure discstem to and maintained in position by means of a clamping ring tocarried by the casing 26.

The bottom wall so oi the chamber 82 is provided with a plurality ofapertures 9t providing passage for fuel from the inlet to to an outlet92 formed in the wall of the casing 26 on the opposite side of thebottom wall so and adapted for connection to the fuel pipe M. Passage offuel through the apertures so is controlled by an auxiliary valve memberto which is movable into and out of engagement with the bottom wall 88of the chamber 32 within which the valve member 94 is located. A valvestem 96 is secured to the valve member 9 3 and extends on either sidethereof. One end of the valve stem 96 is located in chamber 82 andterminates adjacent the diaphragm 84. The auxiliary valve member at isbiased into engagement with the wall 88 by a coil spring 9? carried onthe opposite end of the stem 96 and which is operative between the wall88 and a collar 98 carried on the valve stem 96. This opposite end ofthe valve stem 96 terminates beyond the collar 98 for operativeengagement with a second diaphragm It!) which serves to prevent leakageof fuel from the casing 24 and is held in position by a second clampingring I02 carried on the casing 2%. A reset stem tilt extends fromadjacent the underside of the diaphragm we to the bottom wall of thecasing 2 and is provided with 9, button H16 exterior of the casing 24and by means of which the reset stem 104 may be reciprocated.

The electromagnet, comprising the winding 64 and horseshoe magnet 62, isadapted to be energized by current generated from a thermocouple I08which is connected by suitable leads 0 to the terminal connection 60.The thermocouple I08 is located so that the hot junction thereof will beheated by a flame from a thermocouple heating burner H2 which receives asupply of fuel from the pipe H which also supplies fuel to the flashpilot burner I6. An ignition pilot burner H4 is provided intermediatethe thermocouple heating burner H2 and the main burner [0 to receivefuel from a conduit H6 connected at a junction II! with pipe 18. As willbe more apparent hereinafter, the burner H2 and the portion of the pipe14 beyond branch pipe 16 could be dispensed with if the burner H4 isarranged to heat the thermocouple I08 and also ignite the main burnerIII.

A system of flash tubes is provided for igniting the various burners ofthe system from the constant burning top pilot burner l2. Accordingly, ashort flash tube 8 is provided between the constant burning top pilotburner I2 and the auxiliary pilot burner 12, it being apparent that fuelfrom the pipe 16 flowing from the auxiliary pilot burner 12 will enterthe flash tube H8 and be ignited from the constant burning pilot burnerI2. The flame so created will then be conducted back through the flashtube H8 and will ignite 12. An elongated flash tube I20 is providedbetween the constant buming top pilot burner I2 and the flash pilotburner 10 which is remote therefrom. This flash tube I20 serves to causeignition of the flash pilot burner 10 in a similar manner to thatdescribed in connection with the flash tube I18. In addition, a branchflash tube I22 extends from the flash tube I20 adjacent the flash pilotburner 10 to the thermocouple heating burner H2 and likewise serves toignite the fuel flowing therefrom. It will be understood that if theburner II2 is dispensed with. then the flash tubes I20 and I22 would bearranged to ignite the ignition pilot burner II4 directly instead ofthis burner being ignited from the thermocouple heating burner I I2.

The heat of the flame from the thermocouple heater I I2 on thethermocouple I08 serves to energize the electromagnet sufllciently tohold the armature 66 against the pole faces of the magnet 62 but thisthermoelectric current is incapable of moving the armature to thisattracted position. Hence, resetting means is provided for placing thearmature 66 in attracted position and will now be described inconnection with the detailed views in Figs. 3, 4 and 5 together withthe'more general showing of Fig. l. g

The control device 22 is provided with a bracket I24 extending towardthe top pilot burner I2 and forming a support for the auxiliary pilotburner 12. The bracket I24 is provided with a channel-shaped portion I26at the end opposite the control device 22 and projecting substantiallymidway across the bracket. The channelshap d portion I26 provides spacedbearings for a pivot I28 upon which a latching member I30 is mounted.The latching member I30 is preferably made in two parts, one slidable onthe other which carries the pivot, and biased apart bymeans of a coilspring I32 interposed therebetween. The slidable portion of the latchingmember I30 is provided with a slot I34 extending across one end thereofand offset from the center. Extending between the slot I34 and the resetbutton I06 is a timing device comprising a bimetal strip I36 which isretained in position on the reset button I06 by the provision of atransverse slot I38 disposed centrally thereof. Pivotal movement of thelatching member I30 is restricted by its engagement with a portion ofthe channel-shaped member I26 in a counter-clockwise direction and byits engagement with a set screw I40 carried by the channel-shapedportion I26 in the opposite direction.

As shown more clearly in Fig. 3, when. the re setting button I06 isunoperated, the bimetal strip I36 occupies a position at an angle to theaxis of the control device 22. In this position, the bimetal strip I36is offset from the auxiliary pilot burner '12 which projects through thebracket m substantially midway between the control device 22 and thechannel-shaped portion I26. Manually operated means for moving thebimetal strip I36 and latching member I30 into substantialalignment withthe axis of the conthe fuel flowing from the auxiliary pilot burner Iatlases be subject to the heat of the flame from the auxiliary pilotburner 12. Moreover, in this position the reset button I06 will beforced inwardly of file control device 22 to eflect the resetting opera-The manuall operable means includes a lever I42 provided with an angularportion I44 on one arm thereof having an aperture I46 therethrough inwhich the slidable portion of the latching member I30 is received. Thelever I42 is pivoted on a pin I46 projecting from the bracket I24 on oneside of the channel-shaped portion I28. The other arm of the lever I42is engaged by a flexible connection in the form of a cable or pull wireI66 which is mounted on the bracket I24 and is provided with a coilspring I62 operative between the bracket I24 and the lever I42 forbiasing the lever in a counter-clockwise direction. As shown in Fig. 3.when the lever is thus biased the bimetal strip I36 is held in itsangular position out of the path of the flame from the auxiliary pilotburner 12. I I

The pull wire I50 extends toward the manifold I4 of the range and isconnected by means now to be described with the main fuel cock 20 foroperation by the knob 2|. To this end, the fuel cook 20 is provided witha bracket I54 extending laterally therefrom and carrying a support I56through which the pull wire I50 extends. The end of the wire I50 isconnected to a lever I58 which is pivoted on a pin I60 carried by thebracket I54. Movement of the lever I58 in one direction serves to exerta pull on the wire I50 against the bias of the spring I52 and thuspermits operation of the latching element I30. Such movement of thelever I58 is effected by a slidable member I62 having a hooked end I64adapted to operatively engage the lever I 56. The slidable member I62having a hooked end I64 stantially normal to the axis of the fuel cock26 by means of a toothed portion I66 on the slidable member I62 beingadapted for engagement with a lug I68 carried by the knob 2|.Theslidable member I62 is supported on the bracket I54 and its movementrelative thereto is limited by the provision of a slot I10 formed in theslidable member I62 for cooperation with a pin I12 carried by thebracket I54.

In order that the lug I66 on the knob 2I may pass beyond the toothedportion I66 on the slidable member I62, the latter is yieldably mountedon the bracket I54 to permit such movement. To this end. the slidablemember I62 is maintained with the hooked end I64 thereo in engagementwith the lever I58 by means of a spring wire I14 which ma be mounted atone end on the pin I12 and having its opposite end hooked in aperforation I13 in slidable member I62. A stop in the form of an arm I15is secured to the pin I and engages the bracket I54 to limit movement ofthe lever I58 as will be apparent hereinafter.

embodiment of the invention a second timing.

device I16 is included and is of differentfoi'in from the first timingdevice described comprising the bimetal strip I36 cooperable with theauxiliary pilot burner 12. The second timing device I16 comprises aclock timer I18 of any well known form which is manually adjustable toselected time positions for starting and stopping operation of theapparatus. To this end, the clock timer I18 includes a control valve Ill7 carried by the fuel pipe II between the fuel cock 20 and the junctionIII of pipe H6. The control valve I80 is provided with a valve memberI42 which is operated between open and closed positions by the clocktimer "8 and will prevent flow of fuel to the auxiliary pilot burner I2,the thermocouple heating burner H2 and the ignition pilot burner I I4when closed.

The operation of the apparatus is as follows: The clock timer 8 is firstadjusted to a starting time position and stopping time position and thevalve member I82 consequently will remain closed until the selectedstarting time is reached. The constant burning top pilot burner isassumed to be producing a flame. The fuel cock 20 is then opened bymeans of rotation of the knob 2| in a clockwise direction, as viewed inFig. 4, to cause fuel to flow in the pipe I8 as far as the controldevice 22 and as far as the timing device I16 in pipe I8. This operationof the knob 2I will cause the lug I68 to be moved in a clockwisedirection into engagement with, the toothed portion I66 on the slidablemember I62 causing the pull wire I50 to be operated by means of thelever I68. The latching lever I42 will thus be moved against the bias ofthe spring I52 in a clockwise direction causing the latching element 530to move the adjacent end of the bimetal strip I36, also in a clockwisedirection, until it is aligned with the axis of the control device 22and in the path of the flame from the auxiliary pilot burner I2.

The set screw I40 is now engaged by the latching element I30 and it willbe apparent that the reset button I06 is thus forced inwardly, and ismaintained in such position while the bimetal strip is unheated, due tothe clockwise torque applied at the slot I34 to the bimetal strip I36and the counter-clockwisetorque applied at the set screw I40 to thelatching element I30. The lug I60 on knob 2| has moved under andreleased the toothed portion I66 during the opening movementof cook 20due to the yieldable mounting of the slidable member I62. The resetspring I52 causes the slidable member I62 to be returned to its initialposition as soon as the toothed portion I66 is released from the lugI68. The unheated bimetal strip I36 remains in the latched positionindependent of the force applied by the pull wire I50.

The inward movement of the reset button I06 causes the reset stem I04 tomove the diaphragm I and cause movement of the auxiliary valve stem 86axially against the bias of the coil spring 91 which causes movement ofthe auxiliary valve member 94 from its seat. It is apparent, however,that no fuel can flow to the pilot burners I2, "2 and H4 because theclock valve member I82 is still closed.

During this resetting operation the stem 48 of the closure disc 42 isengaged by the diaphragm 84 and is moved against the bias of the spring50 into engagement with the seat 44. The valve member 36 issimultaneously moved away from its seat 38, but fuel is prevented fromflow-- ing from the passage 32 through the outlet 34 to the main burnerI0 due to the immediate seating of the closure disc 42. It may be notedthat immediately prior to engagement of the closure disc 42 with itsseat 44 that the armature 66 has been placed in contact with the polefaces of the horseshoe magnet 62. However, the closure disc 42 canthereafter be moved into engagement with the seat 44 due to theprovision of the override spring 54 which is compressed during 75 of thethermostat combined with the mainfu'el- 8 such movement, due to therelative movement between the closure disc 42 and the valve stem 40.

When the clock timer "8 reaches its starting time position fuel will beadmitted through pipe I8, inlet and chamber 82 through apertures 00,outlet 92 and pipe I4 to the pilot burners I0 and H2. Simultaneously,fuel flows through the branch pipe I6 to the auxiliary pilot burner I2.ignition of pilot burners I0 and H2 respectively after the auxiliarypilot burner I2 is ignited by flash tube II! from the constant burningpilot burner I2.

After a predetermined time delay, during which the bimetal strip I36becomes sufllciently heated by the flame from the auxiliary pilot burnerI2, the strip warps and trips the latching element I30. This warping ofthe bimetal strip I36 causes the direction of the torque at the slot I34to be changed from clockwise to counterclockwise. Hence, the latchingelement I33 is rotated counter-clockwise when tripped and will move thebimetal strip I36 out of the flame of the auxiliary pilot burner I2 toits initial cold position and simultaneously relieve the force upon thereset button I06.

The system is now in its steady state operating condition. Theretraction of the reset stem I04 has caused the auxiliary valve 94 to bemoved under the bias of the spring 91 into engagement with its seat toprevent flow of fuel from the inlet 80 through the apertures to theoutlet 92 so that the flow of fuel through the pipe I4 to the flashpilot burner I0, thermocouple heating burner I I2 and auxiliary pilotburner 12 is cut off. However,

the time for heating the bimetal strip I36 sumciently to cause it towarp is made long enough so that the thermocouple I08 can becomesufllciently heated by the flame from the thermocouple heating burner H2and the ignition pilot burner H4 to generate current for energizing theelectromagnet before the auxiliary valve 94 is moved to closed position.As the armature 66 is now held in attracted position against the polefaces of the magnet 62, the valve member 36 remains open while theclosure disc 42 becomes disengaged from the seat 44 under the bias ofthe coil spring 50. Flow of fuel from the inlet 26, passage 32 andoutlet 34 to the main burner I0 is now permitted. This burner is ignitedby the flame at the ignition pilo burner II4.

It has been mentioned that the thermocouple heating burner II 2 could bedispensed with if desired provided that the ignition pilot burner II4 bepositioned to ignite the main burner I0 and also heat the thermocoupleI08. Consequently, the flash pilot burner I0 would be located in thepipe H6 and. the flash tubes I20 and I22 rearranged accordingly. Whenthe resetting operation is completed and auxiliary valve 94 closed,

then the flow of fuel to the pilot burner I2 is cutoil. The ignitionpilot burner I I4 would, however, remain in operation as the pipe H6 isconnected to the pipe I8 ahead of the control device 22.

If at any time during the interval between the starting and stoppingtime positions of the clock timer I18 the thermocouple I08 ceases to beheated by the ignition pilot burner H4, then the armature 66 will bereleased from the pole faces of the magnet 62 causing the safety valvemember 36 to close and prevent further flow of fuel to the main burnerI0. Otherwise, the apparatus will operate normally with the main burnerunder control The flash tubes I20 and I22 cause cock 20 until the clocktimer I18 reaches its stopping time position.

At the stopping time position, the clock valve member I82 willautomatically be closed to shutoff the fuel supply in the pipes I8 andH6. The ignition pilot burner I I4 will thus cease to produce a flameand the thermocouple I08 will cool and cause the safety valve 36 toclose. The apparatus is thus arranged for I per cent shutoff of fuelwhenever the clock timer I18 operates to close its valve member I82.

It will be observed that the first and second timing devices describedare operated independently by separate manual means. This arrangementmakes it possible for the latching element I30 to be set at one time andthe timing device therefor, comprising bimetal strip I36, to be set tooperate at any time thereafter under control of the clock timer I18.Thus, although both the latching element I30 and its timing device I36are placed in operative condition by a single manipulation of the handle2|, they are not actually rendered operative until the desired startingtime as set by the clock timer I'I8. Moreover, the thermoelectric safetymeans is caused to serve two useful purposes instead of one. This occursby reason of the use of the thermocouple I08 to determine the stoppingtime for the apparatus under control of the clock timer I I8, as well asits more customary use as a safety device responsive to a pilot burnerflame.

It will be apparent that many changes may be made in the details ofconstruction and arrangement and combination of parts within the scopeof the appended claims without departure from the invention disclosedherein.

I claim:

1. A safety control apparatus for fuel burners having main and pilotburners and a source of fuel supply, comprising electromagnetic meanshaving a member operable between positions for controlling the flow offuel to the main burner and being biased to a fuel supply preventingposition, means responsive to the presence of a flame at the pilotburner for causing energization of said electromagnetic means forholding said member in a fuel supplying position, resetting meansoperable for positioning said member in said position to supply fuel tothe main burner and including a timing device adopted to be conditionedfor terminating the resetting operation upon expiration of apredetermined period during which said flame responsive means has timeto become responsive, conditioning means for rendering said timingdevice effective, and a second timing device controlling saidconditioning means and being adjustable between selected time positionsfor initiating said period at a selected time following operation ofsaid resetting means.

2. A safety control apparatus for fuel burners having main and pilotburners and a source of fuel supply, comprising electromagnetic meanshaving a member operable between positions for controlling the flow offuel to the main burner and being biased to a fuel supply preventingposition, means responsive to the presence of a flame at the pilotburner for causing energization of said electromagnetic means forholding said member in a fuel supplying position, resetting meansoperable for positioning said member in said position to supply fuel tothe main burner and including a timing device adapted to be conditionedfor terminating the resetting operation upon expiration of apredetermined period during which said flame responsive means has timeto become responsive,

conditioning means for rendering said timing device eflective and asecond timing device controlling said conditioning means and havingmeans for controlling the flow of fuel to the pilot burner and beingadjustable between selected time positions for preventing said flowuntil a selected time following operation of resetting means.

8. A safety control apparatus for fuel burners I having a plurality ofburners including main and pilot burners and a source of fuel supplytherefor, comprising electromagnetic means having a member operablebetween positions for controlling the flow of fuel to at least the mainburner and being biased to a fuel supply preventing position, meansresponsive to the presence of a flame at one of said pilot burners forcausing energization of said electromagnetic means for holding saidmember in a fuel supplying position, resetting means operable forpositioning said member in said position to supply fuel to the mainburner and including a timing device operable only when the flame atanother one of said pilot burners has existed for a predetermined periodfor terminating the resetting operation, and a second timing devicehaving means for controlling the flow of fuel to the last said pilotburner and being adjustable between selected time positions forpreventing said flow unti a selected time following operation of saidresetting means.

4. A safety control apparatus for fuel burners having a main burner, apair of pilot burners and a source of fuel supply, comprisingelectromagnetic means having a member operable between positions forcontrolling the flow of fuel to the main burner and being biased to afuel supply preventing position, means responsive to the presence of aflame at one of the pilot burners for causing energization of saidelectromagnetic means for holding said member in a fuel supplyingposition, resetting means operable for positioning said member in saidposition to supply fuel to the main burner and including a deviceresponsive to a flame at the other pilot burner for terminating theresetting operation. and a timing device having means controlling theflow of fuel to at least said other pilot burner and being adjustablebetween selected time positions for preventing said flow until aselected time following operation of said resetting means.

5. A safety control apparatus for fuel burners having a main burner, apair of pilot burners and a source of fuel supply, comprising valvemeans operable between open and closed positions for controlling thesupply of fuel to at least the main burner and being biased to saidclosed, position, electromagnetiemeans operatively associated with saidvalve means for holding the same in open position when energized,thermoelectric means responsive to the heat of a flame at one of thepilot burners and operative for energizing said electromagnetic meanssufilciently to retain said valve means in said open position, resettingmeans operative for positioning said valve means in said open positionand including a flrst timing device responsive to a flam at the otherpilot burner and operativ for terminating the resetting operation. meansoperatively associated with said resetting means for interrupting theflow of fuel to the main burner during theresetting operation, and asecond timing device adjustable to starting and stopping time positionsand having means for preventing flow of fuel to said pilot burnersexcept in the interval between said positions, said first timing devicebeing automatically rendered operative at said starting time 11 and saidthermoelectric means being rendered inoperative at said stopping time.

6. A control apparatus for fuel burners having main-and pilot burners, amain shut-off valve movable between positions for controlling the fuelsupply to the burners, safet shut-off means operabl between positionsfor controlling the fuel supply to at least the main burner and beinglocated remote from the main valve, means for biasing said safety meansto a fuel supply preventing position, operating means for positioningsaid main valve, connecting means between said operating means and saidsafety means for positioning the latter in a fuel supply permitting po-ysition, said connecting means including a timing device adapted to beconditioned during a predetermined period for rendering said connectingmeans inoperative upon expiration of said period, conditioning means forrendering said timing device effective and a second timing devicecontrolling said conditioning means and being adjustable betweenselected time positions for initiating said period at a selected timefollowing operation of said operating means.

7. A control apparatus for fuel burners having main and pilot burners, amain shut-off valve movable between positions for controlling the fuelsupply to the burners, safety shut-off means responsive to a flame atone of the-piot burners and operable between positions for controllingthe fuel supply to at least the main burner and being located remotefrom the main valve, means for biasing said safety means to a fuelsupply preventing position, adjustable operating means for positioningsaid main valve to admit fuel to the burners, connecting means betweensaid operating means and said safety means for positioning the latter toadmit fuel to the main burner,

said connecting means including a timing device,

responsive to a flame at'another of the pilot riod for rendering saidconnecting means inoperative, and a second timing device adjustableindependently of said main valv operating means to starting and stoppingtime positions, said second timing device having means for preventingoperative for opening said safety valve, an auxiliary burner inproximity of said constant burn ing pilot burner, a flash-tube extendingbetween said auxiliary and constant burning pilot burners, meansresponsive to a flame at said auxiliary burner for rendering said valveopening means operative for a predetermined period during which saidthermoelectric generator has time to become heated, and a timing devicehaving means for preventing flow of fuel to said auxiliary and flashpilot burners except during a selected time interval following operationof said valve opening means.

9. Safety control and ignition apparatus for fuel burners comprising incombination, a main burner, a fuel supply pipe connected to the mainburner, means for igniting the main burner in-- cluding a flash pilotburner in proximity of the main burner and having separate connectionwith valve, an auxiliary burner in proximity of said.

constant burning pilot burner, a flash-tube extending between saidauxiliary and constant burning pilot burners, an auxiliary valveyieldingly urged closed, for controlling flow of fuel to said auxiliaryand 'flash pilot burneramanually burners and operable after apredetermined peflow of fuel to the pilot burners except in the 8.Safety control and ignition apparatus forv fuel burners, comprising incombination, a main burner, a fuel supply pip connected to the mainburner, means for igniting said main burner including a flash pilotburner in proximity of the main burner and having separate connectionwith said fuel supply pipe, a constant burning pilot burner positionedremote from said flash pilot burner, a flash-tube extending between saidpilot burners for conducting a flame therebetween, a safety shut-offvalve 'yieldingly urged closed for controlling flow of fuel to said mainand flash pilot burners, electromagnetic means effective when energizedfor holding said safety valve open, a thermoelectric generator adaptedto be heated by a flame at the flash'pilot burner for energizing saidelectromagnetic means but operable means for openingsaid safety andauxiliary valves, means for interrupting new of fuel to th main burnerupon operation of said manually operable means, a latch loperativelyassociated with said manually operable means for holding said valvesopen, a thermal element cooperable with saidlatch and responsive to aflame at said auxiliary burner for causing said auxiliary valve to closeafter said thermoelectric generator has, had time to become heated, anda timing device adjustable to starting and stopping timepositionsstarting time position and said thermoelectric generator beingrendered inoperative atsaid stopping time position. 55

CHARLES K. S'I'ROBEL REFERENCES CITED The following references are ofrecord in the file of this patent:

insufiiciently to open said safety valve, means Mantz June 13, 1944

